Re: Granite surface plate mounting
Depends on how large the surface plate is. I have a 24x18x4 that sits on the end of my work bench. I built a nice heavy 3/4 inch plywood box that covers it. There is no need to have a surface plate perfectly level unless you are planning to somehow use a level on it to measure parts. It is common to 3 or 5 point mount surface plates, depending on size, but unless you are setting up a metrology lab, I don't see the need on smaller plates. I think your leveling feet idea would work fine, but really overkill.
Jim Dawson
Sandy, Oregon, USA